In recent years, owing to the spread of portable information processing apparatuses such as notebook computer, PDA (Personal Digital Assistant), cellular phone, and the like each having a radio communicating function, the user carries those apparatuses into a specific area, connects them to a wired or wireless LAN set in the area, and makes data communication. Therefore, a security technique to prevent illegal communication participation in the network from the information processing apparatuses has been proposed (for example, refer to JP-A-2002-232449).
Specifically speaking, a DHCP server is arranged in an outsourcing center and obtainment of an IP address by the DHCP server is disabled unless otherwise an MAC address has previously been registered. The following technique has been disclosed: when an information processing apparatus such as a computer or the like in which the MAC address is not registered is connected to the network, an enterprise or a group is specified by an authenticating server, thereafter, an MAC address registering display screen to register the MAC address is prepared, correspondence information between the MAC address and an IP address to be used is formed for the DHCP server, the IP address is dynamically searched for from the correspondence information between the MAC address and the IP address which has been registered in a database of the DHCP server, and an IP address for a user's computer is issued.
However, according to the above conventional technique, for example, in the case where, at a place where the user has gone to, he lost the information processing apparatus which had communication—participated in the network in the specific area and the third party uses such an information processing apparatus and illegally accesses the network, there is a fear that secret information or the like managed only in the specific area leaks although a security countermeasure has been made to the entering/leaving of the user into/from the specific area.
For example, as shown in FIG. 1, assuming that reference numeral 113 denotes a radio communicating terminal which is ordinarily used by a regular user 103 in a security area 101 where the secret information is protected and which was lost in the place where he has gone to and 112 indicates a third party who tries an illegal access to the network in the security area 101 by using the communicating terminal 113, according to the security countermeasure technique disclosed in JP-A-2002-232449, it is difficult to sufficiently protect the secret information.
The invention is made in consideration of the above problem and it is an object of the invention to provide a mechanism which can prevent an illegal access to a network or the like set in a specific area and improve a security of the network.